Is this compression fitting safe?

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HitTheTwit

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I had some welding done recently, and the guys hooked me up with a bunch of 1/2" SS compression fittings.

As I worked with them, I began to notice some dark smudges rubbing off on my fingers from the compression nut. The body is definitely and obviously stainless, but the nut is a darker color. Do you guys have any idea what this metal is, and if it's safe to brew with?

Pretty much every dip tube and fitting I have will use one of these, so I'm hoping the answer is yes!

Many thanks!

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It's a molybdenum coating of some kind or another that's on the SS. I talked to a guy at Parker who told me he wouldn't use them in a submerged situation, like in the HLT or BK. If liquid is just running through it then it won't touch the nut anyway. I'm still not sure if there is any real concern if it was submerged in the HLT or BK to be honest though. I just took his word for it. In researching the moly for myself, it didn't seem to sound like a big deal but I swapped them out with some Parker A-lock series just be sure since they're not coated and since the moly stuff seemed to rub off so easily.

So, outside the HLT, MLT, BK, not an issue at all, inside maybe not but I'm not completely sure.
 
Hmm.. I've currently got 6 of them that are supposed to be going into the keggles. Two each for the tubes in the BK and MLT, one for the HLT, and another as a convenient way to pull my Jaybird FB out.

It's sounding like it might be worth switching them out then. Is there any way to remove the moly coating?

And if it does prove worth switching out, where did you pick up the Parker A-lock series nuts? Or did you replace the whole things?
 
Some of us on here bought some of the industrial fittings that you have by mistake from an eBay seller and they switched out the furrules and nuts from the a-lock series. This is the seller and the a-lock series fitting that you want. I don't know that you can get just the ferrules and nuts though. They just did it because the description on the other one's were not completely right.

Before I knew what it was I tried sanding it off. It was a mess and it didn't all come off anyway. Not recommended.
 
PantherCity, it may be totally fine as I said. Just relaying what the guy at the company told me. I would urge anyone with any concern to call Parker themselves and get all the info you can. You never know, a different guy might say something different and as I said, I couldn't find anything concerning when I was looking into it.
 
Jsguitat, thank you for the excellent information! Though not what I wanted to hear...

Can anyone else chime in about these?
 
From what I researched thos are carbon something something, they will rust and not intended for our enviroment. Use stainless and don't take the risk.
 
Bloody hell. I have SS everything else too...
Anyone in SE PA have a tube bender? Sounds like I have to order and make all new fittings
 
I just looked at the three pieces more closely, and it appears that the bolt and compression fitting are regular SS. Hopefully that means I just need to get 1/2" Nuts to replace it.

Although my tubes are already bent, which prevent me from slipping the nuts off... so I'll need to make new dip tubes.

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HitTheTwit said:
Bloody hell. I have SS everything else too...
Anyone in SE PA have a tube bender? Sounds like I have to order and make all new fittings

Ian,
I have a 1/2 tube bender, you can borrow it when you return my grinder :)
 
Turns out that I've got 6 extra ferrules from what they gave me, so I've got to find a place to order 7 nuts.

Fortunately, he also gave me a ton of extra tubing, so I can make some new bends with your help. Thanks Milldoggy!
 
OK, trying another tact here. Moly is indeed rubbing off...but is it safe?

Moly is actually used in 316 SS, to the tune of about 2%. This reduces corrosion and 316 is of course, food safe.

It seems that Parker used a Moly Lubricant on these nuts, but I didn't think to ask how much. The reason I should have asked is that moly is actually an essential part of our diet.

According to WebMD, and agreed on by various other intelligent sounding sources...
Molybdenum is a trace mineral found in foods such as milk, cheese, cereal grains, legumes, nuts, leafy vegetables, and organ meats. The amount in plant-derived foods depends on the soil content in the growing area. Molybdenum is also present in water in varying amounts. Molybdenum is stored in the body, particularly in the liver, kidneys, glands, and bones. It is also found in the lungs, spleen, skin, and muscles. About 90% of the molybdenum eaten in foods is eliminated by the body through the urine.

How does it work?

Molybdenum works in the body to break down proteins and other substances. Molybdenum deficiency is very uncommon.

Molybdenum has an important role in normal body functions, but there is not enough information to know how it might work for any medical condition.

Molybdenum is LIKELY SAFE when used appropriately by adults. Molybdenum is safe in amounts that do not exceed 2 mg per day, the Tolerable Upper Intake Level.

For children, molybdenum is LIKELY SAFE in amounts that do not exceed the UL of 0.3 mg per day for children 1 to 3 years, 0.6 mg per day for children 4 to 8 years, 1.1 mg per day for children 9 to 13 years, and 1.7 mg per day for adolescents.

However, molybdenum is POSSIBLY UNSAFE when used in high doses. Adults should avoid exceeding 2 mg per day. Children should avoid exceeding 0.3 mg per day for children 1 to 3 years, 0.6 mg per day for children 4 to 8 years, 1.1 mg per day for children 9 to 13 years, and 1.7 mg per day for adolescents.


So the question is how much Moly rinses off per batch. I'm guessing it's less than 2mg...

This being said, I went the all SS route because I didn't want random **** in my beer, and this is about as random as it gets. I'll get my system built using these current fittings, but will order more A Lok SS nuts to build better tubes soon. Fortunately, it seems that I live near some pretty awesome type people who can hook me up with everything from a bench grinder to a tube bender (thanks Milldoggy!).

If any engineers want to weigh in here to tell me Moly is totally safe, I'd appreciate it. Otherwise, on to Plan B.

PS. I did speak with a Parker Engineer, and he told me they weren't recommended for submerged applications. He didn't say unsafe though.
 
Ian,
Why take the chance. I have a bunch on spare compression fittings, I will sell them to you at cost, think it was 5.99 each. I think I have 4 1/2 ones.
 
HitTheTwit, I'm glad you called them. The thing is, there is also a bonding agent used with the moly, so it's not just pure moly. There's no telling what that is and the guy I talked to wasn't all that specific either other than not recommending it. I agree with milldoggy that since it's not clear whether it's safe and nobody else seems to know, and the fact that the manufacturer doesnt reccommend it that it's probably better not to use them just to be on the safe side.


An after thought: Parker doesn't come right out and say it, but if you look at the bottom of this page, in the grey box, you'll see they tested 'bonded' molybdenum and talk about the 'binder', whatever that is.

Ok, no more raining on your parade! Just lookin' out.
 
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